Question

23. (Crystal Field Theory) which one of the following statements is FALSE?
O
A. In an octahedral crystal field, the d electrons on a metal ion occupy the eg set of orbitals
before they occupy the tag set of orbitals.
O B. Diamagnetic metal ions cannot have an odd number of electrons.
O C. Low spin complexes can be paramagnetic.
D. In high spin octahedral complexes, Aoct is less than the electron pairing energy, and is
relatively very small.​

Answer 1

Answer:

Option A is false

In an octahedral crystal field, the d electrons on a metal ion occupy the T2g set of orbitals before they occupy the Eg set of orbital.

Answer 2

Answer:

a) is the wrong option.

Explanation:

In an Octahyderal complex when the d-orbital split into $t_2g$ and $e_g$. $t_2g$occupies the lower energy while eg occupies higher energy. And according to Aufbau principle the electrons are first filled in the lower energy orbitols. So $t_2g$ is filled before $e_g$.

Low spin complexes can be paramagnetic if they have unpaired electrons.

High spin complexes do have a smaller delta value compared to pairing energy that is why they choose to jump to $e_g$ levels instead of pairing.